from __future__ import absolute_import
from __future__ import division
from __future__ import unicode_literals
from __future__ import print_function

import os
from torch.utils.data import Dataset
import numpy as np
import pickle
from dataloaders.rawvideo_util import RawVideoExtractor
from . import video_container as container
from . import decoder as decoder
from . import utils as utils
from ipdb import set_trace
class MSVD_DataLoader(Dataset):
    """MSVD dataset loader."""
    def __init__(
            self,
            subset,
            data_path,
            features_path,
            tokenizer,
            max_words=30,
            feature_framerate=1.0,
            max_frames=100,
            image_resolution=224,
            frame_order=0,
            slice_framepos=0,
    ):
        self.data_path = data_path
        self.features_path = features_path
        self.feature_framerate = feature_framerate
        self.max_words = max_words
        self.max_frames = max_frames
        self.tokenizer = tokenizer
        # 0: ordinary order; 1: reverse order; 2: random order.
        self.frame_order = frame_order
        assert self.frame_order in [0, 1, 2]
        # 0: cut from head frames; 1: cut from tail frames; 2: extract frames uniformly.
        self.slice_framepos = slice_framepos
        assert self.slice_framepos in [0, 1, 2]

        self.subset = subset
        assert self.subset in ["train", "val", "test"]
        video_id_path_dict = {}
        video_id_path_dict["train"] = os.path.join(self.data_path, "train_list.txt")
        video_id_path_dict["val"] = os.path.join(self.data_path, "val_list.txt")
        video_id_path_dict["test"] = os.path.join(self.data_path, "test_list.txt")
        caption_file = os.path.join(self.data_path, "raw-captions.pkl")

        with open(video_id_path_dict[self.subset], 'r') as fp:
            video_ids = [itm.strip() for itm in fp.readlines()]

        with open(caption_file, 'rb') as f:
            captions = pickle.load(f)

        video_dict = {}
        for root, dub_dir, video_files in os.walk(self.features_path):
            for video_file in video_files:
                video_id_ = ".".join(video_file.split(".")[:-1])
                if video_id_ not in video_ids:
                    continue
                file_path_ = os.path.join(root, video_file)
                video_dict[video_id_] = file_path_
        self.video_dict = video_dict

        self.sample_len = 0
        self.sentences_dict = {}
        self.cut_off_points = []
        for video_id in video_ids:
            assert video_id in captions
            for cap in captions[video_id]:
                cap_txt = " ".join(cap)
                self.sentences_dict[len(self.sentences_dict)] = (video_id, cap_txt)
            self.cut_off_points.append(len(self.sentences_dict))

        ## below variables are used to multi-sentences retrieval
        # self.cut_off_points: used to tag the label when calculate the metric
        # self.sentence_num: used to cut the sentence representation
        # self.video_num: used to cut the video representation
        self.multi_sentence_per_video = True    # !!! important tag for eval
        if self.subset == "val" or self.subset == "test":
            self.sentence_num = len(self.sentences_dict)
            self.video_num = len(video_ids)
            assert len(self.cut_off_points) == self.video_num
            print("For {}, sentence number: {}".format(self.subset, self.sentence_num))
            print("For {}, video number: {}".format(self.subset, self.video_num))

        print("Video number: {}".format(len(self.video_dict)))
        print("Total Paire: {}".format(len(self.sentences_dict)))

        self.sample_len = len(self.sentences_dict)
        self.rawVideoExtractor = RawVideoExtractor(framerate=feature_framerate, size=image_resolution)
        self.SPECIAL_TOKEN = {"CLS_TOKEN": "<|startoftext|>", "SEP_TOKEN": "<|endoftext|>",
                              "MASK_TOKEN": "[MASK]", "UNK_TOKEN": "[UNK]", "PAD_TOKEN": "[PAD]"}

    def __len__(self):
        return self.sample_len

    def _get_text(self, video_id, caption):
        k = 1
        choice_video_ids = [video_id]
        pairs_text = np.zeros((k, self.max_words), dtype=np.long)
        pairs_mask = np.zeros((k, self.max_words), dtype=np.long)
        pairs_segment = np.zeros((k, self.max_words), dtype=np.long)

        for i, video_id in enumerate(choice_video_ids):
            words = self.tokenizer.tokenize(caption)

            words = [self.SPECIAL_TOKEN["CLS_TOKEN"]] + words
            total_length_with_CLS = self.max_words - 1
            if len(words) > total_length_with_CLS:
                words = words[:total_length_with_CLS]
            words = words + [self.SPECIAL_TOKEN["SEP_TOKEN"]]

            input_ids = self.tokenizer.convert_tokens_to_ids(words)
            input_mask = [1] * len(input_ids)
            segment_ids = [0] * len(input_ids)
            while len(input_ids) < self.max_words:
                input_ids.append(0)
                input_mask.append(0)
                segment_ids.append(0)
            assert len(input_ids) == self.max_words
            assert len(input_mask) == self.max_words
            assert len(segment_ids) == self.max_words

            pairs_text[i] = np.array(input_ids)
            pairs_mask[i] = np.array(input_mask)
            pairs_segment[i] = np.array(segment_ids)

        return pairs_text, pairs_mask, pairs_segment, choice_video_ids

    def _get_rawvideo(self, choice_video_ids):
        video_mask = np.zeros((len(choice_video_ids), self.max_frames), dtype=np.long)
        max_video_length = [0] * len(choice_video_ids)

        # Pair x L x T x 3 x H x W
        video = np.zeros((len(choice_video_ids), self.max_frames, 1, 3,
                          self.rawVideoExtractor.size, self.rawVideoExtractor.size), dtype=np.float)

        for i, video_id in enumerate(choice_video_ids):
            video_path = self.video_dict[video_id]

            set_trace()
            raw_video_data = self.rawVideoExtractor.get_video_data(video_path)
            raw_video_data = raw_video_data['video']

            if len(raw_video_data.shape) > 3:
                raw_video_data_clip = raw_video_data
                # L x T x 3 x H x W
                raw_video_slice = self.rawVideoExtractor.process_raw_data(raw_video_data_clip)
                if self.max_frames < raw_video_slice.shape[0]:
                    if self.slice_framepos == 0:
                        video_slice = raw_video_slice[:self.max_frames, ...]
                    elif self.slice_framepos == 1:
                        video_slice = raw_video_slice[-self.max_frames:, ...]
                    else:
                        sample_indx = np.linspace(0, raw_video_slice.shape[0] - 1, num=self.max_frames, dtype=int)
                        video_slice = raw_video_slice[sample_indx, ...]
                else:
                    video_slice = raw_video_slice

                video_slice = self.rawVideoExtractor.process_frame_order(video_slice, frame_order=self.frame_order)

                slice_len = video_slice.shape[0]
                max_video_length[i] = max_video_length[i] if max_video_length[i] > slice_len else slice_len
                if slice_len < 1:
                    pass
                else:
                    video[i][:slice_len, ...] = video_slice
            else:
                print("video path: {} error. video id: {}".format(video_path, video_id))

        for i, v_length in enumerate(max_video_length):
            video_mask[i][:v_length] = [1] * v_length

        return video, video_mask

    def _get_rawvideo_yb(self, choice_video_ids):
        video_mask = np.zeros((len(choice_video_ids), self.max_frames), dtype=np.long)
        max_video_length = [0] * len(choice_video_ids)

        # Pair x L x T x 3 x H x W
        video = np.zeros((len(choice_video_ids), self.max_frames, 1, 3,
                          self.rawVideoExtractor.size, self.rawVideoExtractor.size), dtype=np.float)
        
        for i, video_id in enumerate(choice_video_ids):
            video_path = self.video_dict[video_id]

            raw_video_data = self.rawVideoExtractor.get_video_data(video_path)
            raw_video_data = raw_video_data['video']

            

            video_container = container.get_video_container(
                    path_to_vid=video_path,
                    multi_thread_decode=False,
                    backend="pyav",
                )


            frames, vid_len = decoder.decode(
                video_container,
                sampling_rate=3,
                num_frames=12,
                clip_idx=1,
                num_clips=1,
                video_meta=None,
                target_fps=1,
                backend="pyav",
                max_spatial_scale=0,
                use_offset=False,
            )
            
            
            frames = utils.tensor_normalize(
                frames, [0.48145466, 0.4578275, 0.40821073], [0.26862954, 0.26130258, 0.27577711]
            )

            # Normalize((0.48145466, 0.4578275, 0.40821073), (0.26862954, 0.26130258, 0.27577711))
            # [0.485, 0.456, 0.406]
            # [0.229, 0.224, 0.225]
            # [0.45, 0.45, 0.45]
            # [0.225, 0.225, 0.225]
            

            # if len(raw_video_data.shape) > 3:
            #     raw_video_data_clip = raw_video_data
            #     # L x T x 3 x H x W
            #     raw_video_slice = self.rawVideoExtractor.process_raw_data(raw_video_data_clip)
            #     if self.max_frames < raw_video_slice.shape[0]:
            #         if self.slice_framepos == 0:
            #             video_slice = raw_video_slice[:self.max_frames, ...]
            #         elif self.slice_framepos == 1:
            #             video_slice = raw_video_slice[-self.max_frames:, ...]
            #         else:
            #             sample_indx = np.linspace(0, raw_video_slice.shape[0] - 1, num=self.max_frames, dtype=int)
            #             video_slice = raw_video_slice[sample_indx, ...]
            #     else:
            #         video_slice = raw_video_slice

            #     video_slice = self.rawVideoExtractor.process_frame_order(video_slice, frame_order=self.frame_order)

            #     slice_len = video_slice.shape[0]
            #     max_video_length[i] = max_video_length[i] if max_video_length[i] > slice_len else slice_len
            #     if slice_len < 1:
            #         pass
            #     else:
            #         video[i][:slice_len, ...] = video_slice
            # else:
            #     print("video path: {} error. video id: {}".format(video_path, video_id))

        for i, v_length in enumerate([int(vid_len)]):
            if vid_len > self.max_frames:
                video_mask[:] = 1
            else:
                video_mask[i][:v_length] = [1] * v_length
                

        if vid_len < self.max_frames:
            frames[int(vid_len):] = 0

        frames = frames.permute(0,3,1,2).unsqueeze(0).unsqueeze(2)

        return frames, video_mask

    def __getitem__(self, idx):
        video_id, caption = self.sentences_dict[idx]

        pairs_text, pairs_mask, pairs_segment, choice_video_ids = self._get_text(video_id, caption)
        video, video_mask = self._get_rawvideo(choice_video_ids)
        # video, video_mask = self._get_rawvideo_yb(choice_video_ids)



        return pairs_text, pairs_mask, pairs_segment, video, video_mask
